Finite Drude weight for one-dimensional low-temperature conductors

We apply well-established finite-temperature quantum Monte Carlo techniques to one-dimensional Bose systems with soft- and hard-core constraints, as well as to spinless fermion systems. We give clear and robust numerical evidence that, as expected, no superfluid density for bosons or Meissner fraction for fermions is possible at any nonzero temperature in one-dimensional interacting Bose or Fermi lattice models, whereas a finite Drude weight is generally observed in gapless systems, in partial disagreement with previous expectations.